The xemacs program is currently built as a position-dependent executable (i.e., not PIE), which means no address space layout randomization (ASLR) hardening. I wonder if it possible to use the portable dumper and enable full ASLR.
I know that ASLR breaks some XEmacs configurations, but I'm not certain if it breaks all of them. I will experiment this weekend and see if something can be done.
ASLR conflicts with the techniques XEmacs uses to build both the portable dumper and the garbage collector. Enabling ASLR would require architectural changes that are unlikely to happen now, given that upstream is very nearly dead. While I am technically part of upstream myself, I never worked on either the dumper or the garbage collector, so am unfamiliar with that code. I think we have to leave hardening disabled on this package for it to function.
This bug appears to have been reported against 'rawhide' during the Fedora 29 development cycle. Changing version to '29'.
I do not believe there is anything that can be done about this (with a reasonable amount of effort anyway), so I am closing this bug.